1. Field of the Invention
This invention relates to separation, identification, quantification and evaluation of intact microbes and cells by electrokinetic separation systems that employ small passageways with a fluid therein and electrical forces to cause movement in the passageway, such as capillary electrophoresis, capillary isoelectric focusing, or microchip fluidic systems. The method of the present invention is especially well suited for diagnosis of disease and for use in industries such as food, biotech and military where the presence or absence of microbes is key to an analysis.
2. Art Related to Invention
Microbes or microorganisms are small complex organic systems which are capable of reproduction, some on their own and some only in a host. They include bacteria, fungi, algae, viruses, yeast, spores, and protozoa.
The process for separation and identification of microbes is largely dominated by 19th century procedures of growing and isolating pure cultures. This is a slow and tedious process that works only for a small fraction of microbes. There are many microbes that still cannot be isolated and identified in this manner. Furthermore, such a process does not allow for the rapid differentiation between various microbes in a complex mixture nor quantification and evaluation of the microbes.
Electrokinetic separation techniques are well known. Capillary electrophoresis, capillary isoelectric focusing, isotacophoresis and gel electrophoresis are conventional techniques which are typically used to separate and isolate chemical compounds. They have never been successfully employed for separation, identification, quantification and further evaluation of intact microbes and cells.
Microchip fluidic systems are a relatively new electrokinetic separation technique. Examples of this technique can be found in U.S. Pat. No. 6,046,056 issued Apr. 4, 2000; U.S. Pat. No. 6,045,676 issued Apr. 4, 2000; U.S. Pat. No. 6,042,710 issued Mar. 28, 2000; and U.S. Pat. No. 6,033,546 issued Mar. 7, 2000. The devices employed in microchip fluidic systems are often referred to as microchip capillary devices, microfabricated devices, and microfluidic devices. Such devices are usually made from silicon, quartz, glass or polymers such as poly(dimethylsiloxane). In essence, they are miniaturized capillary systems which have a number of advantages over conventional capillary systems, the primary one being size.
Electrokinetic techniques have been employed to analyze the contents of lysed cells, however, these methods have not proven to work with lysed microbes and mixtures of lysed microbes to allow unambiguous identification of microbes. One of the problems is that different microbes often have similar intracellular structures, thus once the microbe is lysed, each microbe looks alike.
There is a need for a simple, quick analytical technique which would allow for separation, identification, quantification and evaluation of microbes.